| 摘要 |
PROBLEM TO BE SOLVED: To surely present a supporting strength in tight contact with a solidified foot protection liquid over entire surfaces of protrusions of a precast pile inside of a foot protection part.SOLUTION: A bottom-end precast pile 1 to be used includes annular protrusions 5, 6 which are positioned in a foot protection part of a pile hole. A protection tube 11 to be used is configured by connecting operating rods 15, 15 to an upper end of a tubular substrate 11 covering at least the protrusions 5, 6 of the precast pile 1 and consecutively providing a rubber closing member 13 abutted to a bottom face of the precast pile 1 in a lower end (Figure 1). Along the outer circumference of the precast pile 1, the protection tube 11 is mounted so as to cover the protrusions 5, 6. In such a state, protrusions 4, 5 are positioned in a foot protection part 66 of a pile hole 65 by lowering the precast pile 1 while drilling the pile hole with a drill head 20 similarly to a normal hollow trench pressing fit technique. The drill head 20 is pulled up onto the ground, continuously, the operating rods 15 are pulled onto the ground, and the protection tube 10 is pulled up onto the ground. The protrusions 4, 5 to which mud is not deposited are buried within the foot protection part 66. |
